Solid state electric cell utilizing as an electron acceptor material an organic ammonium polyiodide



Nov. 4. 1969 B. B. OWENS 3,476,505

CELL UTILIZING AS AN ELECTRON ACCEPTOR C AMMQNIUM POLYIODIDE SOLID.STATE ELECTRIC MATERIAL AN ORGANI Filed July 6, 1967 FIG. 2

INVENTOR.

BOONE B. OWENS ATTORNEY United States Patent Ofiice 3,476,605 PatentedNov. 4, 1969 ABSTRACT OF THE DISCLOSURE An organic ammonium polyiodidecathode component for a solid state electric cell containing a silveranode and an ionically conductive silver-containing solid electrolyte.The polyiodide compositions utilizable as electron-acceptor cathodecomponent are defined as QI where Q is an organic ammonium cation,preferably a quaternary ammonium cation, and n has a value ranging from2 to 11, inclusive. Specifically preferred polyidodide compositions aretetramethylammonium heptaiodide N (CH .gI- and the tetraethylammoniu mtriiodide N (CQH5 1: and heptaiodide N (C2H5) 4L7- C'ROSS REFERENCES TORELATED APPLICATIONS The improved cathodes of the present invention maybe utilized with the inorganic solid ionic conductors and electric cellscontaining these conductors as solid electrolyte element which aredisclosed in copending applications Ser. No. 569,193, 573,743, and573,744 all filed Aug. 1, 1966, and assigned to the assignee of thepresent application. The cathodes of this invention are of particularutility in the electric cells having conductive organic ammonium silveriodide salts as solid electrolyte element, which are disclosed incommonly assigned copending application Ser. No. 651,499 filed of evendate herewith.

BACKGROUND OF THE INVENTION This invention relates to solid stateelectric cells having improved cathode compositions. It moreparticularly relates to such solid state electric cells having anionically conductive silver composition as solid eletcrolyte element.

Solid state electric cells utilizing a solid ionic conductor aselectrolyte are known and are generally advantageous compared withconventional cells and batteries with respect to shelf-life stability,leak-free properties, freedom from pressure buildup during theelectrochemical reaction, and flexibility with respect to constructiondesign and miniaturization. One cell employing silver iodide as thesolid electrolyte is described in US. Patent 2,689,876, Soild IonElectrolyte Battery. Improved solid state cells having a solidelectrolyte of higher ionic conductivity than that of silver iodide aredisclosed in the referred-to copending applications Ser. Nos. 569,193,573,743, and 651,499. These cells generally utilize silver as theelectrondouor anode material and a nonmetal capable of functioning as anelectron acceptor for the cathode material. Several such cathodematerials are shown in US. Patent Re. 24,408. Iodine dispersed in acarbon matrix is generally preferred as cathode material, although otheriodine sources such as a mixture of Ag S and I Rbl Csl and NH I havealso been suggested. Since iodine may be lost by diffusion orevaporation, the cell is generally encapsulated with a protective resinor other material.

However, the use of pure iodine as a cathode material has been founddisadvantageous because of the occurrence of cell corrosion, loss incell stability, and poor shelf life due to excessively high iodineactivity, resulting in reaction of iodine with the solid stateelectrolyte or the other cell components. Attempts have been made to usethe inorganic alkali metal polyiodides, e.g., RbI 051 as cathodecomponents. While this results in a lowering of the iodine activity,there is a substantial increase in material costs and a loweravailability of iodine based on unit weight of the cathode component.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an improved iodine-source cathode material for a solid stateelectric cell. It is a further object to provide a cathode material thatis particularly compatible for use with organic ammonium silver iodideelectrolytes.

In accordance with the present invention there is provided a solid stateelectric cell having an improved cathode. The cell comprise-s aconductive anode, preferably of silver, an ionically conductive solidstate silver ion electrolyte, and a cathode composition including anorganic ammonium polyiodide component as the electron-acceptor cathodematerial. The organic ammonium iodide salts may be expressed by theempirical formula Ql Q being a univalent organic ammonium cation,preferably a quaternary ammonium cation. I is an anionic polyiodidecomplex having a net charge of minus one, n having a value between 2 and11, inclusive, preferably between 3 and 7. The nitrogen of the organicammonium cation complex may be attached to separate organic groups ormay form part of a cyclic structure.

Because of chemical reaction between the organic ammonium polyiodidecathode component and the silverion electrolyte at thecathode-electrolyte interface, an organic ammonium silver iodide saltwill be formed. It is preferred that this formed salt be of relativelyhigh ionic conductivity, i.e., greater than that of silver iodide, toavoid degradation of the cell current. A high-conductivity reactionproduct is obtained where Q is an organic ammonium cation having anionic volume between 30 and cubic angstroms, as more fully described incopending application Ser. No. 651,499, filed of even date herewith andincorporated herein by reference.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross sectional view of anidealized embodiment of a solid state electric cell provided by thisinvention; and

FIG. 2 is a cross sectional view of a preferred embodiment of anelectric cell of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The electron-acceptor cathodecomponent of the present invention may be utilized in any solid stateelectric cell having a conductive-anode electron donor, preferablysilver, and a solid electrolyte wherein the current preferably istransported by silver cations. The cathode compositions QI provide alower iodine activity compared with that of pure iodine and generallyalso the inorganic polyiodides, resulting in greater cell stability,longer shelf-life, and less corrosion. The iodine activity may beexpressed as the ratio of the equilibrium vapor pressure of iodine inthe polyiodide compound to that of pure 1;. A suitable range of activitywill be from 10 to 1. For electric cells operating over a widetemperature range, from 50 C. to C., a preferred range of iodineactivity of the polyiodide is from 10 to 10 For low temperatureoperation, higher iodine activity is preferred, from 10' to 10 at roomtem perature from 10 to 10- at elevated temperatures, activities as lowas 1O are suitable. Since the iodine activity is related to theelectromotive force of the cell as described by the well-known Nernstequation, the activity of the iodine may be expressed in terms of cellvoltage itself Generally, the desired Q11, component is incorporated inthe cathode composition in a standard test cell, and the open-cellvoltage is measured. For a pure iodine cathode, an open cell voltage ofabout 0.67 volt is obtained. A suitable range of cell voltages for thepractice of the present invention lies between 0.60 to 0.665. Cellvoltages below 0.60 are unduly limiting with respect to the current thatmay flow. Cell voltages above 0.665, which is that obtained using RbI ascathode composition, are indicative of excess iodine activity andcharacterize cells having poor stability. Thus, the selection of aspecific electron-acceptor cathode component Ql represents a balancebetween desired current flow and increased iodine activity, and will bedetermined by the particular cell characteristics desired and planneduse' of the cell.

The value of n in QI will vary from 2 to 11, with compositions betweenQ1 and Q1 being generally preferred. Particularly preferred compositionsare N(C H I and N(C H I- For increasing values of 11, particularly above9, the equilibrium vapor pressure of the iodine in the compoundcorrespondingl increases and may become excessive, approaching that ofpure iodine, because all the iodine cannot be bound by the Q cationcomplex. In general, as the formula weight of Q is increased, the valueof n will be increased in order not to unduly lower the amount ofavailable iodine on a weight percentage basis. The formula weight of Qand the value of 11. may be correlatively selected to provide apreselected value of iodine activity. Also,

Q1. (or; I.)

may represent a single material or a mixture of several materials havingdifferent n values to provide an averaged composition of empiricalformula QI Q may be any cationic organic ammonium complex. However, somereaction does occur between Ag ion and QI at the electrolyte-cathodeinterface to form an organic ammonium silver iodide composition. Thus itis generally preferred that these formed compositions at the interfacebe conductive so as not to unduly degrade or limit the current-carryingcapacity of the cell. Therefore, the limitations imposed with respect toQ as set forth in copend ing application Ser. No. 651,499 are also usedherein for the preferred organic ammonium iodide compounds. Thefollowing is a more detailed description of a preferred characterizationof Q. Thus, in its preferred aspects Q is defined as an organic ammoniumcation having a cationic volume between 30 and 85 A. (cubic angstroms).Where the substituents on the nitrogen atom of Q are aliphatic groups,e.g., methyl, ethyl; or aralkyl groups, e.g., benzyl; then Q preferablyis a quaternary ammonium ion; i.e., four carbon atoms are attached tothe nitrogen atom. The nitrogen atom of the organic ammonium cationcomplex may be attached to separate organic groups or may be part of theheterocyclic compound.

For an acrylic organic ammonium ion, i.e., one where the nitrogen is notpart of the ring structure, and the substituents are aliphatic oraralkyl groups, it has been found that four carbon atoms must be linkedto the nitrogen atom; that is, the ammonium compound is a quaternaryammonium compound in its strictest sense, no hydrogen being attached tothe nitrogen atom. Where the four R groups are aliphatic substituents,it has been found that the total number of carbon atoms present may varyfrom four to nine. Illustrative of suitable aliphatic substituent groupsfor attachment to the nitrogen atom of the quaternary ammonium cationcomplex are Me Me Et, Me Pr, Me3i-PI, MezEtz, MeEt MBEtgPI', McEt i-Pr,Etg, MeEt Bu, Et Pr, Me Ay, where Me=methyl, Et=ethyl, Pr=propyl,i-Pr=isopropyl, Bu=butyl, and Ay=ally1.

The molecular volumes for these quaternary ammonium cations range from42 to 80 A Because of the ready availability of the starting materials,the satisfactory polyiodide iodine activity, and the high conductivityof the resultant quaternary ammonium silver iodides that may be formed,the lower alkyl groups, particularly methyl and ethyl, are preferred assubstituent groups.

Substituents other than aliphatic groups may also be attached to thenoncyclic nitrogen atom provided the volume of the resulting cation Q+is between 30 and A Thus, carbocyclic, aryl and benzyl substituents maybe attached in addition to aliphatic ones. Illustrative of such suitablesubstituent groups are trimethylcyclohexyl, trimethylphenyl andtrimethylbenzyl.

The nitrogen atom may also form part of a cyclic structure. Illustrativeof suitable cations are azacyclic: N,N-dimethylpyrrolidinium;azabicyclic: 8,8-dimethyl-8- azoniabicyclo[3.2.l]octane; azoniaspiro:5-azoniaspiro- [4.4]nonane; and heterocyclic: pyridinium,N-methylpyridinum, a-picolinium, N-methylquinolinium,N-methylacridinium, 1,1,2-trimethylpyrrolium, and N,N-dimethylindolium.

The size of the cation Q+ is one of the important parameters determiningthe conductivity of the organic ammonium silver iodide salts. For a highionic conductivity (defined as greater than that of silver iodide), thesize of the organic cation is between 30 and 85 A.

The values for the volume of the cationic complex are determined byusing the molecular volumes for the corresponding hydrocarbon analogsaccording to the equation 1 MW 7.228 cl where V represents the molecularvolume in cubic angstroms, MW is the molecular weight, and d is thecritical density in grams per cubic centimeter. Critical density valuesfor hydrocarbons are readily available in the literature or convenientlyestimated. Since molecular volume V is proportional to the Van der Waalsconstant b, and b is universally proportional to the critical density dthe molecular volume can be readily calculated.

The calculated volumes for the hydrocarbon analogs correspondapproximately to those of the organic ammonium cations since the CC bondand the CN bond r are almost the same length and the Q+ cation isisoelectronic with its hydrocarbon analog. Thus a good approximation tothe size (volume) of Q+ is the volume of the isoelectronic hydrocarbon.

Determination of the molecular volume of the hydrocarbon analog permitsa ready selection of suitable organic ammonium cations. For example,using the upper limit of 85 A. and where all four substituents are notaliphatic groups, it is readily determined that about five carbons canbe added to a cation containing a phenyl group, about five carbons to apyridyl system, about three in a quinolyl system, and four to five ifthere is a cyclo hexyl group as substituent. Thus, Et C H N+ would beone of the largest allowable cations containing a phenyl group. If thephenyl group itself is substituted with alkyl groups or separated fromthe nitrogen by methylene groups, then the carbon content of the othersubstituents attached to the nitrogen atom would have to beproportionately reduced to maintain the desired upper limit of cationicvolume.

The polyiodide compositions may be prepared by combining the organicammonium iodide with a desired molar portion of iodine and heating themixture in a closed vessel at a temperature between 60 and C. and thenquenching the product. Or the cathode composition may be prepared byfirst blending the quaternary ammonium iodide with carbon and aconductive electrolyte and then heating the mixture with iodine. In US.Patent 3,028,427 are shown methods for the preparation of variousquaternary ammonium iodide compouuds used as germicidal compositions.

In FIG. 1 is shown a cross sectional view of an idealized embodiment ofa solid state electric cell provided by this invention. The severallayers are shown in a nonscalar simplified form, an anode 1 consistingof any suitable metallic conductor which functions as an electron donor.Preferably, silver is used as the anode material, as a thin sheet orfoil, although copper and other conductive materials may also beutilized. The electrolyte 2 comprises any silver-ion solid statematerial such as the silver halides or Ag SI, and preferably the ionicconductive compositions shown in copending application Ser. No. 569,193and Ser. No. 651,499. The cathode 3 heretofore has consisted of anonmetallic electron acceptor as shown, for example, in US. Patents2,690,465, 2,696,513 and Re. 24,408, generally elemental iodine preparedas an intimate mixture of carbon and iodine. Electrical leads (notshown) are conventionally attached to the anode 1 and cathode 3.

The advantages provided by the present invention are obtained by usingan organic ammonium polyiodide material as the electron acceptorcomponent of the cathode 3, thereby lowering the iodine activity andproviding increased cell stability and shelf-life without unduedegradation of the current-carrying capacity of the cell.

The most advantageous results in the practice of this invention areobtained when both the anode and cathode of the solid state electriccell are of composite structure and contain dispersed solid electrolytematerial therein, as shown in FIG. 2. This solid state cell constructionis essentially that shown in the referred-to pending application S.N.573,744. Where only a Single composite electrode is used, theperformance of the cell will be improved by making either electrode acomposite one. The dispersed electrolyte preferably should benonreactive with the materials used for cathode and anode.

Referring to FIG. 2 a preferred embodiment of a solid state electriccell construction is shown in which both the anode and cathode containdispersed electrolyte and in which an electronically conductive materialoverlays the composite cathode layer and is in contact with the cathodecomposition but not coextensive therewith. The composite anode consistsof an electronically conductive layer 4, e.g., silver, in contact with amixed anode layer 5 of silver which contains dispersed therein carbonand electrolyte material. A method of preparing a particularly preferredsilver-containing anode composition is described and claimed incopending application S.N. 615,351 and reference should be made theretofor a more detailed description. An electrolyte layer 6 is selected fromionically conductive silver-ion compositions, particularly RbAg I KAg Iand NH Ag I as shown in copending application S.N. 569,193 and theorganic ammoniurn silver iodide compositions as shown in copendingapplication S.N. 651,499. The composite cathode consists of a layer 7 ofthe organic ammonium polyiodide component together with carbon andelectrolyte material dispersed therein. The relative amounts of carbon,electrolyte, and polyiodide are not critical and may be varied over awide range. Preferably, the relative amounts of three components of thecathode blend may vary, on a wt. percent basis, from -80 polyiodide,5-60 carbon, and 10-50 electrolyte. The electrolyte material present inthe composite anode and cathode is preferably of the same composition asthe material used for electrolyte element 6. A preferred solid statecell includes a silver-containing anode, a solid electrolyte elementcomprising N(CH Ag I and a polyiodide-containing cathode comprising N(CH I Where the solid electrolyte element is RbAg I or KAg I it ispreferred to use a polyiodide-containing cathode having a higher iodinecontent, e.g., a cathode comprising 2 5)4 7- For preferred polyiodidecompositions QI utilized for the cathode component, Q is a quaternaryammonium cation whose substituents are selected from methyl and ethylradicals and n varies from 3 to 9. As a matter of preferredconstruction, layer 7 has been shown as not being coextensive withconductive layer 8 so as to avoid possible shortcircuiting of the cell.Thereby, the organic ammonium polyiodide, which has a certain vaporpressure of iodine, is also more conveniently retained in the carbonmatrix. Layer 8 consists of a suitable electronically conductivematerial nonreactive with the cathode material, e.g., tantalum,molybdenum, niobium, carbon, or various conductive plastics which areessentially nonreactive with iodine, particularly where the iodine has alower activity, which occurs when an organic ammonium polyiodide isutilized as the electron acceptor material. Electrical leads (not shown)are conventionally attached to the anode and cathode conductive layers 4and 8 respectively.

The following examples are illustrative of the practice of thisinvention with respect to preferred embodiments relating to solid statecells utilizing improved cathode compositions. These examples should notbe construed as limiting with respect to optimization of cell currentand voltage, which are functions of the material selected for theelectrodes and electrolyte, cell constniction tech niques, and internalresistance of the cell as determined by electrolyte layer thickness,contact resistance between adjacent layers, and other related cellparameters. For a solid state cell having a conductive silver anode anda silver ion electrolyte, the cell voltage will generally be a functionof the cathode composition, although the current obtained will bedependent upon the other parameters as described. Optimization of theseseveral parameters may be achieved by routine experimentation inaccordance with the teachings of this invention and the known artrelating to solid state cells.

Example 1.Preparation of quaternary ammonium polyiodides A molar portionof tetramethylammonium iodide was reacted with varying molar portions ofiodine in a closed vessel at a temperature of 65 C., the molar amountsof iodine used varying from 1 to 3 moles I per mole oftetramethylammonium iodide. Polyiodide compositions were obtained in allinstances, having an empirical formula ranging from N(CH ).,I toN(CH3)4I7, the equilibrium vapor pressure of the polyiodide productsincreasing with increasing iodine content but being substantially belowthat of pure iodine. Similar polyiodide products were prepared byperforming the reaction at C. followed by quenching of the reactionproduct. These techniques of preparation were also used to prepare otherpolyiodide compounds QI Several typical preparations are shown asfollows:

To 12.16 g. of (C H NCH I was added 12.7 g. of I As soon as the I wasadded, the contents changed to a black liquid. After 1 /2 hr. no smellof I was detectable and the contents started to harden.

To 13.56 g. of (C H NC H I was added 12.7 g. of I the contents becomingliquid upon I addition. After 1 /2 hr. the contents were hard and blackin color. No odor of I was detectable.

To 13.16 g. of (CH NC H I was added 12.7 g. of I The compounds wereblended together, forming a silver blue-green product. After 1 /2 hr., aslight odor of I was noted.

To 14.96 g. of C2H5N(C3Hq)3I was added 12.7 g. of I the contentsbecoming liquid. After 1 /2 hours the contents were almost hard, butstill wet. No odor of 1 was noted.

To 15.66 g. of N(C3H7)4I was added 12.7 g. of I The contents wereblended together, no liquid being formed. After 1 /2 hr. the mix turnedgreen in color and had a strong pungent odor.

To 10.05 g. of N(CH I was added 12.7 g. of I The contents were blendedtogether, no liquid being formed. After 1 /2 hr. the contents turnedgreen in color. No odor of I was detectable.

Example 2.Preparation of cathode blend Cathode blends of l g.electrolyte, l g. carbon, and 3 g. polyiodide (varying from N(C H I toN(C H I were prepared by melting RbAg I electrolyte together monthsstorage, flash currents for the best of these cells had decreased froman initial value of 120 ma. to 0.2 ma., and from an initial value of 100ma. to 1 ma., thereby demonstrating the enhanced stability obtained byuse of an organic ammonium polyiodide composition as electron with thecarbon, blending in tetraethylammonium iodide, 5 and heating to 120 C.with iodine. While a suitable blend ag gg g f o1 iodide cathode ma wasobtained, the utilization of I was only about 75%. terials advanstlaeons com afedywith ure iodine in Utilization approaching 100% wasobtained when carbon l 1 P d d H was first blended with an aqueoussolution of tetraethyla ower 10 me activlty resu ting In re uce Ceammonium iodide and the blend was then dried and 10 corroslon andlonger. i i further advan' powdered and added to an acetone solution ofRbAg I tageous (.Wer h i morgamc p i p as .RbI3 The acetone wasvaporized off from the mixture the 0r.CSI3 m provldmg lower. lqdmeactwlty a hlgher recovered product was dried and powdered and thedewel-gl-1t pe-rcent of avallable Iodine lower cost nonresired amount ofiodine was then added The mixture was actlvlty Wit-h the electrolytes Plong?! heat m d for 18 hours at 115 C fou'owed b 48 hours cellshelf-like, and greater compatibility wlth orgamc 2 e y ammonium silver1od1de electrolytes. at It will of course be understood that manyvariations Example 3.-Electric cell using organic ammonium can be madewith respect to the solid state electric cells polyiodide cathodecomposition of the present invention characterized by an improvedElectric cells were prepared having a structure corre- 2O Qathodecomposltlfm Wlthout departmg from the inven' Sponding to that Shown in 2The anode Composi tive concept herern. Improved features of constructiontion consisted of a blend of Silver carbon and RbAg4I5 used forconventional solid state electric cells, in order The electrolyteelement was RbAg I The cathode comto mi Polarization and assure f e31151 anpde position was prepared essentially as described for ExampleStability e e llke, y be y ll'illlled Wlth t e 2 d i t d f b RbAg I d horganic or no modification of the preferred cell construction ilmoniumpolyiodide. The measured cell voltages are shown lustrated herein. Thefurther advantages are obtained of in Table 1. highly superior electriccell characteristics, particularly TABLE l.EMF OF ELECTRIC CELLS l lgtIa/Q nl Wt. Open Percent Circuit Available EMF QL, in Cathode 1;;(volts) (CH3)4NI3 56 0. 655 (CH3)4NI4-. e4 0. 643 (CH3)4N 73 O. 652(CH3)4NIO 76 0. 667 (oHmN so 0. 667 (CH3)3NC2H5I3. 54 0. 652CH3N(C2H5)3I3 51 0. 64 (CzH5)4NIa 50 O. 640 (CzHshNh 67 0. 643 (C2Ha)aNx 1 48 0. 633 o 46 0.614 (0311 N 0. s04 a 1)4 5 63 0. 625 (O3H7)4N 72 0.657 (CH3)3NCH5I; (Trimethylphenylammonium triiodide).. 49 0. 639 C9H1NH13 (Quinolinium triiodide) .t 50 0. 655 CnH1NHI5 (Quinoliniumpentaiodide) t 66 0. 657 CqHyNCH I (l-methylquinolinium triiodide) 48 0.648 CQH7NOH3I5 (Lmethylquinolinium pentaiodid 65 0. 650 C5H5NCH3I3(l-methylpyridinium triiodide)..- 53 0. 658 O5H5NCH3I5(l-methylpyridiniurn pentaiodide) 70 0. 661

For a representative cell, using N(C2H5)4I7 as electronlong shelf-life,as well as stability over a wide temperaacceptor cathode component, thetotal cathode weight ture range, because of the improved cathodecomposi- (grams) of the constituents used for the cathode blend is:tions used in the present cells. Also, while the present electric cellis of principal interest and utility as a primary l fg %%3 miniamp 55cell, it may also be utilized as a secondary cell, particularly byselecting the polyiodide cathode electron ac- For a 200 milliamp.-hr.cell, there is utilized 2.08 g. cathceptOr so as to produce a reactionproduct with silver ganode, and gtroly e, Or 8 1200 having a lowerdecomposition potential than that of the milliamp.-hr., calculating to apower denslty of 13.0 wattsolid electrolytes themselves. hr./lb.Accordingly, while the principle of the invention and Example 4.Electriccell using organic ammonium its Preferred {node of Operation have beenexplained in compositions fo electrolyte and cathode accorlancie wlththe patent bstatutes,b and what is now consi ere to represent its est emodiment has been A test Structure slmllar that of w illustrated anddescribed, it should be understood that prepared having an anodecomposition (1 g.) consisting 5 of Ag, 0, and RbAg I pyn'diniumheptasilver octaiodide, Wthm the 9 the.aPPended l the C5H5NHAg7I8 (3 g),as electrolyte; and a cathode may be practiced otherwise than asspeclfically lllustrated position (1 g.) consisting of carbon, RbAg Iand and N(C H I The open circuit voltage obtained was 0.66 I volt with aflash current of 650 milliamperes. Aften seven A a State eleetrle cellhavlng an a cathode, months storage, the open circuit voltage was 0.64volt e a 5011(1 electrolyte dISPOSed thefebetweel'l p and the flashcurrent was 150 milliarnperes. tlve relation, wherein the improvementcomprises a cath- Similar cells were also prepared using organic amodeutilizing as electron acceptor material an organic monium silver iodideelectrolytes, but using Rbl as the ammonium polyiodide having theempirical formula QI electron acceptor in a composite cathode. Afterseven where Q is an organic ammonium cation having an ionic volumebetween 30 and 85 cubic angstroms and n has a value from 2 to 11.

2. A cell according to claim 1 where Q is an aliphatic group-substitutedquaternary ammonium cation Where the total number of carbon atoms in thegroups attached to the nitrogen atom varies from 4 to 9.

3. A cell according to claim 2 Where the four groups attached to thenitrogen atom of the quaternary ammonium cation are selected from methyland ethyl groups.

4. A cell according to claim 3 where Q has the formula N(CH and n has avalue ranging from 3 to 7.

5. A cell according to claim 3 where Q has the formula N(C H and n has avalue ranging from 3 to 7.

6. A cell according to claim 5 where QI is N(C H I 7. A solid stateelectric cell according to claim 1 wherein said anode comprises silver,said solid electrolyte is a silver-ion electrolyte selected from theclass consisting of KAg I RbAg I NH Ag I and QAg I and mixtures thereof,and the cathode comprises QI the value of a being between 3 and 39 and nhaving a value from 2 to 11.

8. A cell according to claim 7 wherein said anode comprises an intimatemixture of silver, carbon, and solid electrolyte material, and saidcathode comprises an intimate mixture of carbon, QI and solidelectrolyte.

9, A cell according to claim 7 wherein the solid electro UNITED STATESPATENTS Re. 24,408 12/1957 Hack et a1. 136--83 2,689,876 9/ 1954 Lehovec136--100 2,690,465 9/1954 Broder 136-153 2,696,513 12/1954 Lehovec 136833,379,569 4/1968 Berger et a1. l36--6 2,905,740 9/1959 Smyth et a1136-83 3,057,760 10/1962 Dereska et al. 136-137 WINSTON A. DOUGLAS,Primary Examiner A. SKAPARS, Assistant Examiner U.S. Cl. X.R. 136-153 333 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, *75 Dated November LI, 1969 Inventofls) Boone B. Owens It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 56, "Soild" should read --Solid-- Column 3, line 61,"acrylic" should read -acyclic-- Column 10, lines 1 and '7, for eachoccurrence after "Q is" insert --an aliphatic group-substitutedquaternary ammonium cation where the four groups attached to thenitrogen atom of the quaternary ammonium cation are-- Signed and sealedthis L .th day of May 1971.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. WILLIAM E. SCHUYLER, JR. Attesting OfficerCommissioner of Patents

